Around 70,000 BCE, early Homo sapiens at Blombos Cave in South Africa created geometric engravings on pieces of ochre, featuring complex cross-hatched patterns. These deliberately made abstract markings represent one of humanity's earliest known forms of symbolic expression. The engravings demonstrate early humans' capacity for abstract thinking and non-verbal communication through symbols. These artifacts, along with shell beads and specialized tools found at the same site, suggest that these early human communities possessed cognitive capabilities for creating and understanding symbolic representations long before the development of formal writing systems.